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2006 Ticking noise when engine runs

Discussion in 'Gen 2 Prius Technical Discussion' started by richiemoe2, Sep 27, 2023.

  1. richiemoe2

    richiemoe2 Junior Member

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    My 2006 Toyota Prius with 260k miles, has a substantial ticking sound. It sounds exactly like a stuck or loose lifter. It has made this noise for a while, but it has always been quiet. It had recently gotten louder. So before I changed the oil, I put in sea foam, and the noise went away. So I assumed it was a stuck lifter. I put in new NAPA Full Synthetic High Mileage oil and the noise was LOUD!!!!

    But I didn't see any codes, other than the codes that I've had for a while.... Bad tire pressure sensors and the mass air flow sensor. The exhaust has rusted through the pipe behind the CAT flange, but just before the muffler. After my son played in the car and turned on all of the lights, i detached the battery, trickle charged it, and we took the top of the engine off. None of the bolts on the cams were loose. No noticeable wear... We did check the spark plugs too, but those were recently replaced about 3.5years ago... The left 2 sparks plugs were "more dirty", but overall, they all looked like normal. So we wire brushed them and put everything back together. The noise is still there, and we're thinking it is due to pressure with the exhaust leak, as the noise seems to vary from RPM speeds, idle and driving. But none of it is consistent.... I did order a MAF sensor this morning and it will be here Friday. When I drove the vehicle yesterday, it STRUGGLED to accelerate compared to normal!!!! But there are no new codes showing up on the dash.... Just the tire sensors that are bad....

    I did run techstream last night and there are no codes showing up in that either, just the tires. I did run an active test for misfire.
    EWMA MISFIRE: 0
    MISFIRE RATE: 9
    MISFIRE RATE1: 1
    MISFIRE RATE2: 1
    MISFIRE RATE3: 7
    MISFIRE RATE4: 0
    What does this mean? Everything that I've read shows that this could be a sign of the bad MAF sensor?
    Could the exhaust leak be an issue? Clogged CAT? If the oil pump was bad, there would be dash lights/codes, right? Could the coil packs be going bad? I was going to put some JB weld on the exhaust leak as a temp bandaid, but the ticking noise is loud, so i'm having trouble locating the leak... I think I recall it being just before the CAT??? During testing on techstream, I did notice that when I had my foot on the gas peddle in park, it did not tick much. But in idle it was loud. And after the car made a noise, like the thermostat opening, I would push on the gas, but the RPM's didn't go up.... Versus when I drove it, the tick noise is loud! The car is on ramps right now... My thoughts are that if the MAF doesn't fix it, i'll go rent a compression tester for each cylinder?

    Thoughts??? The car has 260k miles. But it has ran like a CHAMP!!! Minus this issue, i'd have zero second thoughts about jumping in for a 12 hour road trip each way! Since we bought it at 94k-ish miles, the only issues(minus maintenance) are a bad water pump and I replaced the hybrid battery pack. This car is a champ! I'd like to get 300k-350k miles out of it, while we continue to save up cash for a newer vehicle. But this is my work vehicle right now.
     
    #1 richiemoe2, Sep 27, 2023
    Last edited: Sep 27, 2023
  2. Tombukt2

    Tombukt2 Senior Member

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    This is my work vehicle right now mine's an '09 360,000 new battery about a year ago or something like that everything good The ticking noise You have to isolate that to the engine or chassis components like an exhaust leak a ticking should not be from an exhaust leak unless it's moving a heat shield or something then that can get to fooling you pretty good. Mine is missing most of the heat shields the cat is original It's been attempted to been stolen twice or three times never got past just starting to cut on the pipe. My engine uses some oil but for a 1NZ at this kind of mileage with questionable care prior to me is not unheard of to say the least. But other than that it's spot on a constant 40 to 46 mi to the gallon we drive the car it doesn't drive us so on and so forth. Maybe isolate that ticking a little better The spark plugs don't sound like they were a huge problem I would think the coil shouldn't be either I didn't look at your profile to see where you are but these coils the original that came with the car generally last a very long time. But like all the electronics some fail before others and you deal with that accordingly generally that style coil now is made by a lot of aftermarket manufacturers that do a good job with it of course there are a few that do not.
     
    #2 Tombukt2, Sep 27, 2023
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  3. richiemoe2

    richiemoe2 Junior Member

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    The ticking/knocking noise is definitely coming from the engine. It is very loud in the bottom/back of the engine, when my head is by the exhaust manifold. Since the noise went away when I added sea foam, i'm thinking it is a pressure issue, not bent valve??? If I do a compression test, i could try starting the car with a spart plug out, and see if there is spark, right? I think the coils are original, maybe replaced before we got it at 94k miles?? But the gas mileage has been great! There was a little bit of loss of power before we took the top of the engine off, but this is bad! So either we didn't plug something back in properly, or it has just gotten worse... The exhaust leak is so far back, I can't imagine that being the issue now... Before, i was thinking it remembered it by the CAT, but I might be thinking of our '95 Wrangler.......
     
    #3 richiemoe2, Sep 27, 2023
  4. Tombukt2

    Tombukt2 Senior Member

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    If cylinders are really misfiring The car will set OBD2 codes to confirm this so you don't have to take coils and leave plugs off and try to start the engine and all this kind of nonsense and just gets really kind of messy and if you're missing generally you will know it the engine is running terribly You can't be missing the spark plug or two or beat way out of time of those two items that you will never forget it.
     
    #4 Tombukt2, Sep 27, 2023
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  5. Mpdcnva

    Mpdcnva Member

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    Has the engine ever run low on oil? I do know, one drive low on oil will take this engine out. Are your misfires injector related? Ours ran bad, misfires, was noisy, but no rod knock, and 36 mpg on a good day. Your noise, that you are making it sound like. Is the knock like a ball peen hammer hitting sound?
     
    #5 Mpdcnva, Sep 28, 2023
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  6. Mpdcnva

    Mpdcnva Member

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    Or here’s a test I have done (gen3 technique for clearing the coolant from the cylinders). And it’s a wild test for a Prius if you have never done it. Make sure your hybrid battery is on the high end and do not do it more than twice. Take the spark plugs out, unplug your injectors, clear everything out and away from the engine compartment and hit the start button. The hybrid system will spin the engine (trying to start) and the engine will sound like it’s running (it’s like a 5 to 10 second spin of the engine). If your knock is still present, I would assume you have spun a bearing or you have a wrist pin or mechanical issue. DO NOT do this if you can not clear the codes, as the system will throw several codes for a no start situation. If you have techstream, you do not need to disconnect the injectors; you simply command the engine to spin. The key is to let the engine spin without compression. A solid engine will sound like a smooth running engine without spark plugs.
     
    #6 Mpdcnva, Sep 28, 2023
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  7. richiemoe2

    richiemoe2 Junior Member

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    The codes haven't popped pack up yet.... But if there is misfires, and the acceleration is throttled, what I have read does point to the MAF sensor. But, I'm having trouble understanding how it would can the engine noise?!?!?
     
    #7 richiemoe2, Sep 28, 2023
  8. richiemoe2

    richiemoe2 Junior Member

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    it hasn't ran any lower than a quart, and that has only been when i knew I was changing the oil soon, so i didn't fill it back up. but it hasn't been lower than the bottom marker. it uses some oil, but isn't too bad. the sound is definitely more of a ticking/knocking sound...
     
    #8 richiemoe2, Sep 28, 2023
  9. richiemoe2

    richiemoe2 Junior Member

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    Oh wow, I haven't heard of this test before! I was going to take out each spark plug and see if there is spark, with a compression tester in place of the spark plug. All of the codes were cleared when I took out the 12v battery to charge, after my son drained the battery while playing with the lights. The odd thing, none of the codes have come back on yet, just the bad tire sensor codes...

    I tried running the compression test within techstream, but I clearly wasn't doing something right....
    The directions say:
    1. Select "Cranking Request" and select ON.
    2. Press brake pedal and hold.
    3. Push and hold IG switch.
    4. Release brake pedal.
    5. Press and continue to hold accelerator pedal, even when the engine stops cranking.
    6. To stop active test, push IG switch again and turn IG OFF.
    7. Restart test to check the next cylinder.

    Was I suppose to take a spark plug out for each test???? ha But how would it test compression with a spark plug out...
     
    #9 richiemoe2, Sep 28, 2023
  10. Mpdcnva

    Mpdcnva Member

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    A true compression test; all spark plugs must be removed. The only sealed cylinder has the compression tester threaded into that cylinder.
     
    #10 Mpdcnva, Sep 28, 2023
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  11. richiemoe2

    richiemoe2 Junior Member

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    That is true, I forgot about that. My cousin reminded me about that when I picked up his compression test kit. I ended up not testing compression, it was too nice out, so we used the boat one last time... But I took the car in the next morning, Monday, and they said it needed a new engine, for $4,900. I don't plan to go that route, with a car that has 260k miles... But, my dad sent me a link that shows I can access the crankshaft from the bottom of the car, by removing two oil pans. So i think that i'll try that route. Could be some worn out bushings around the crankshaft. The youtube video made a very similar tapping sound as well, and was a Gen 2 prius like mine!
     
    #11 richiemoe2, Oct 11, 2023
  12. richiemoe2

    richiemoe2 Junior Member

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    Here is the video that I found, in case it might help someone else out too.
     
    #12 richiemoe2, Oct 13, 2023
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